LAN91C100FD_08 Datasheet, PDF (38/77 Pages) SMSC Corporation – FEAST Fast Ethernet Controller with Full Duplex Capability

FEAST Fast Ethernet Controller with Full Duplex Capability
BANK3
OFFSET
0 THROUGH 7
NAME
MULTICAST TABLE
TYPE
READ/WRITE
SYMBOL
MT
LOW
BYTE
MULTICAST TABLE 0
0
0
0
0
0
0
0
0
HIGH
BYTE
MULTICAST TABLE 1
0
0
0
0
0
0
0
0
LOW
BYTE
MULTICAST TABLE 2
0
0
0
0
0
0
0
0
HIGH
BYTE
MULTICAST TABLE 3
0
0
0
0
0
0
0
0
LOW
BYTE
MULTICAST TABLE 4
0
0
0
0
0
0
0
0
HIGH
BYTE
MULTICAST TABLE 5
0
0
0
0
0
0
0
0
LOW
BYTE
MULTICAST TABLE 6
0
0
0
0
0
0
0
0
HIGH
BYTE
MULTICAST TABLE 7
0
0
0
0
0
0
0
0
The 64 bit multicast table is used for group address filtering. The hash value is defined as the six most
significant bits of the CRC of the destination addresses. The three msb's determine the register to be used
(MT0-MT7), while the other three determine the bit within the register.
If the appropriate bit in the table is set, the packet is received.
If the ALMUL bit in the RCR register is set, all multicast addresses are received regardless of the multicast
table values.
Hashing is only a partial group addressing filtering scheme, but being the hash value available as part of
the receive status word, the receive routine can reduce the search time significantly. With the proper
memory structure, the search is limited to comparing only the multicast addresses that have the actual
hash value in question.
BANK 3
OFFSET
8
NAME
MANAGEMENT INTERFACE
HIGH
BYTE
FLTST
MSK_
CRS100
0
0
1
1
LOW
BYTE
0
0
1
1
TYPE
READ/WRITE
SYMBOL
MGMT
0
MDOE
0
0
1
MCLK
MDI
0
MDI Pin
1
MDO
0
Revision 1.0 (09-22-08)
Page 38
DATASHEET
SMSC LAN91C100FD Rev. D